复合碳源饲粮在不同碳氮比下对黑水虻幼虫生长性能和虫体营养成分含量的影响

Effects of Compound Carbon Source Diets with Different Carbon to Nitrogen Ratios on Growth Performance and Body Nutrient Contents of Black Soldier Fly(Hermetia illucens)Larvae

本试验旨在探讨2种类型饲粮碳源在不同混合比例及不同饲粮碳氮比条件下对黑水虻幼虫生长性能和虫体营养成分含量的影响。试验采用两因素试验设计,选用遗传背景相同、同一批次、发育正常、体尺及体重(体重约为11.33 mg/头)一致的3日龄黑水虻幼虫45000头,随机分为25个处理,每个处理3个重复,每个重复600头虫。同时,以花生粕为氮素原料,添加由易生物利用碳源葡萄糖和难生物利用碳源木屑组成的5种不同比例碳源[100∶0(P100)、75∶25(P75M25)、50∶50(P50M50)、25∶75(P25M75)和0∶100(M100)],制作碳氮比分别为10、15、20、25和30,共配制25种不同碳源和不同碳氮比的黑水虻幼虫饲粮,并调节初始水分含量为72%。试验过程中,出现10只幼虫化蛹时停止试验。结果表明:1)与其他处理相比,P100处理在碳氮比为20及以上时,基质相对含水量(RMC)达到139%以上,黑水虻幼虫存活率显著降低(P<0.05)。在相同碳源条件下,碳氮比提高,黑水虻幼虫产率、虫体增重率和百头虫重均呈逐渐下降趋势。2)随着饲粮木屑添加比例的提高,黑水虻幼虫虫体粗蛋白质、粗纤维和粗灰分含量在各碳氮比条件下显著提高(P<0.05),相反,虫体粗脂肪含量在各碳氮比条件下显著降低(P<0.05)。P75M25和P50M50处理虫体粗脂肪含量在碳氮比为25时较高,分别为47.88%和46.57%,均显著高于其他处理(P<0.05)。3)通过正交偏最小二乘(OPLS)法建模与变量投影重要性指标(VIP)分析,RMC和有效碳氮素比例的VIP值均大于0.8,2类配料指标对黑水虻生长性能和虫体营养成分含量影响的贡献最为显著;同时,总碳氮比(TC/TN)和各碳组分与总氮(TN)之比对幼虫指标影响不显著。综上所述,黑水虻幼虫饲粮添加复合碳源,难生物利用碳源占比不应超过25%;选择易生物利用碳源作为外加碳源,碳氮比应控制在20以下且RMC低于139%;RMC和TC/TN在黑水虻饲粮配料中存在一定局限性,RMC和有效的碳氮素比例显著影响黑水虻幼虫生长性能和虫体营养组成,在黑水虻饲粮配料时更应被关注。

This experiment was conducted to investigate the effects of two types of dietary carbon sources with different mixing ratios and different dietary carbon to nitrogen(C/N)ratios on growth performance and body nutrient contents of black soldier fly(Hermetia illucens)larvae.Forty⁃five thousand 3⁃day⁃old black soldier fly larvae with the same genetic background,the same batch,normal development,and the same body size and body weight(about 11.33 mg/head)were randomly divided into 25 treatments with 3 replicates per treatment and 600 larvae per replicate.Meanwhile,using peanut meal as nitrogen raw material,a total of 25 diets for black soldier fly larvae with five different ratios of carbon sources[100∶0(P100),75∶25(P75M25),50∶50(P50M50),25∶75(P25M75)and 0∶100(M100)],which were composed of easily bioavailable carbon source glucose and difficultly bioavailable carbon source wood chips,and with C/N ratios of 10,15,20,25 and 30 were prepared,and the initial water content was adjusted to 72%.The experiment was stopped when 10 larvae pupated during the experiment.The results showed as follows:1)compared with the other treatments,when the C/N ratio was 20 or above,the relative moisture content(RMC)of substrate in P100 treatment was more than 139%,and the larval survival rate was significantly decreased(P<0.05).Under the same carbon source conditions,with the increase of C/N ratio,the larval yield,body weight gain rate and a hundred worm weight of black soldier fly larvae showed a gradual decline.2)With the increase of dietary wood chip ratio,the body contents of crude protein,crude fiber and crude ash of black soldier fly larvae were significantly in⁃creased under each C/N ratio(P<0.05),on the contrary,the body ether extract content of black soldier fly larvae was significantly decreased under each C/N ratio(P<0.05).The body ether extract content in P75M25 and P50M50 treatments was higher when the C/N ratio was 25(47.88%and 46.57%),which was signifi⁃cantly higher than that in the other treatments(P<0.05).3)Through orthogonal partial least square(OPLS)modeling and variable importance in projection(VIP)analysis,the VIP values of the RMC and ratio of availa⁃ble carbon and nitrogen were all greater than 0.8,and the two types of component indices contributed most sig⁃nificantly to the growth performance and the body nutrient contents of body of black soldier fly larvae.At the same time,the total carbon to total nitrogen(TC/TN)ratio and the ratio of carbon components to total nitro⁃gen(TN)had no significant influence on larval indices.In conclusion,when compound carbon sources are added into the diet for black soldier fly larvae,the proportion of difficultly bioavailable carbon sources should not exceed 25%.When easily bioavailable carbon sources are selected as external carbon sources,the C/N rati⁃o should be controlled below 20 and RMC should be lower than 139%.RMC and TC/TN ratio have some limi⁃tations in the dietary ingredients of black soldier fly larvae,which RMC and available carbon and nitrogen ratio significantly affect the growth performance and body nutrient composition of black soldier fly larvae,and should be paid more attention in dietary ingredients of black soldier fly larvae.